The present invention relates to an apparatus for the insertion of the weft thread on a shuttleless loom, having a band wheel which is driven in alternating direction of rotation, a flexible insertion band which bears an insertion member and which, while winding and unwinding on the circumference of the band wheel, is imparted an oscillating movement transverse to the warp threads, and a guide member for preventing the insertion band from lifting off from the circumference of the band wheel.
In one apparatus of this type, known from U.S. Pat. No. 4,010,776, several guide means are provided which are formed by elements in the shape of leaf springs bent at their one end, which grip over the insertion band at their bend end. These elements are fastened at their other end to the band wheel. In the vicinity of the circumference of the band wheel there are provided wedge-shaped control members, fixed in space, against which the guide members run and are thereby pushed away from the band wheel.
In this known apparatus, due to the sliding contact between guide and control members, there is very extensive stressing and wear at least of the control members, and a considerable development of heat. Furthermore, guide and control members constitute an additional and considerable source of noise on the loom. All of these disadvantageous properties of the known apparatus are further increased and even multiplied by the fact that the control members are arranged in the vicinity of the cicumference of the band wheel and therefore in a region of maximum relative speed between guide and control members.
In another apparatus of the aforementioned type known from U.S. Pat. No. 2,604,123, the guide members are formed by rollers which are supported along the circumference of the band wheel and press against the insertion band from the outside. These rollers have, to be sure, proven satisfactory with low speeds of insertion, but with the high speeds of insertion which are today desired, they become very hot and are subject to great wear. Furthermore, the rollers represent a considerable source of noise and also extensively wear down the insertion band.